Preheat oven to 450°F. Arrange quartered tomatoes cut-side up on a large cookie sheet or two 9x13 inch baking dishes in a single layer. Drizzle with 2 tablespoons of olive oil, then sprinkle with 1/2 teaspoon salt and some pepper.

Roast tomatoes for 30-35 minutes until softened with caramelized edges. Let cool slightly.

In a large pot over medium-high heat, add remaining 2 tablespoons of olive oil and the diced onion. Sauté, stirring often, until the onion is soft and translucent, about 5-7 minutes.

Add the minced garlic and cook for another minute until fragrant.

Add the roasted tomatoes with all their juices, peels, and seeds to the pot.

Add the chicken broth, basil, Italian seasoning, remaining salt, and sugar to the pot.

Use an immersion blender to blend everything in the pot until smooth. Alternatively, carefully transfer to a regular blender and blend in batches.

Let the soup come to a gentle simmer for about 30 minutes, stirring occasionally.

Remove the pot from heat and stir in the heavy cream. If desired, strain through a wire mesh strainer for ultra-smooth texture before adding cream.

Serve hot with grilled cheese sandwich and a green salad.